The proposed research will take a concept from a laboratory device to an instrument suitable for commercial application. When mammalian cells are cultured on small gold film electrodes, the impedance of these electrodes measured with a weak AC signal reflects the behavior of the cells. One can detect, in real time, changes in cell morphology including spreading and cell motion. The efficient production of these electrodes is the main technical hurdle in developing a commercial version of this instrument. Phase I demonstrated that photoresist lithography is an excellent approach. Phase II will extend this research to fabricate electrode arrays that are user ready and suitable for tissue culture applications. In addition, the electrical instrumentation will be simplified and the software further developed and rewritten in a window format. With the completion of Phase II, for the first time, an instrument will exist that can electrically probe subtle morphological changes of cells in culture. Dose-response curves to drugs and toxins can be obtained with little manual labor and novel medical applications might move the instrument into clinical use.